Steady State

Checking the Steady State box will turn off the simulation time options and a single steady state analysis will be performed when the when the Run function of the Run Manager is selected.

Simulation Time Options

When performing an EPS, many modeling parameters are dependent on analysis timesteps (intervals) and duration. The following durations and time steps may be specified:

  • Duration – Total length of a simulation in hours. Use 0 to run a single period (snapshot) hydraulic analysis.

  • Hydraulic Timestep – Time interval between re-computation of system hydraulics. Normal default is 1 hour.

  • Pattern Timestep - Time interval used with all time patterns. Normal default is 1 hour.

  • Quality Timestep – Time interval between routing of water quality/temperature constituent.  Normal default is 5 minutes (0:05 hours).  It is important for a water quality/temnperature analysis that this value be no greater than 1/10 the hydraulic timestep.

  • Report Timestep – Time interval between times at which computed results are reported.  Normal default is 1 hour.

  • Rule Timestep - Time interval for which Rule Based Logic Control rules are evaluated.  For greater accuracy, use a rule timestep that is 1/10 the hydraulic timestep.

  • Pattern Start - Hours into all time patterns at which the simulation begins (e.g., a value of 2 means that the simulation begins with all time patterns starting at their second hour). Normal default is 0.

  • Report Start - Hours into simulation at which computed results begin to be reported.  Normal default is 0.

  • Start Clocktime - Clock time  (e.g., 7:30 am, 10:00 pm) at which simulation begins.  Default is 12:00 am (00:00 - midnight).

Once a simulation time is created, it can be associated with any scenario specified by the user or evaluated at any time via selection from the Run Manager.